如何在mongoose中进行查询

let UserSchema = new Schema({
created: {
    type: Date,
    default: Date.now,
    required: true
},
username: {
    type: String,
    unique: true,
    required: true
},
password: {
    type: String,
    required: true
},
role: {
    default: 'user',
    type: String, //we can consider using array of strings as in case user has several roles at the same time
    requierd: true
},
devices: [
    {
        id: '1',
        permissions:['start','stop']
    },

    {
        id: '2',
        permissions:['start','restart']
    }
]
});
let UserSchema = new Schema({
created: {
    ty